Heating or cooling installation control valves are applied in hydraulic heating or cooling installations, in order to closed-loop control the fluid flow. In particular, such valves for example are applied as mixing valves, in order to mix two fluid flows, in particular fluid flows of a different temperature. Such mixing valves are applied in heating or cooling installations, in order to be able to closed-loop control the feed temperature to a desired value.
Known valves for example comprise three connection channels, e.g. two entries and an exit which run out in a valve space in, in which a movable valve element is arranged, by way of whose displacement the run-outs or mouths of the connection channels into the valve space can be reciprocally closed and opened. For this, valve seats or seals are arranged in the region of the run-outs of the connection channels, in the valve space. These must be inserted into the valve space either through an assembly opening, through which the valve element is inserted, or through one of the connection channels. With the assembly through the connection channels, there is the disadvantage that the complete valve unit must be separated from connecting conduits for the maintenance and replacement of the valve seats.